Like filing your taxes on time, taking proper care of your contact lenses—and your eyes, by extension—is something you know you should do. Then why, pray tell, is it so tempting to slack on the contact lens job?

The annoying truth is that you’re rolling the dice with your eye health if you don’t have great contact habits. Contact lenses are considered medical devices for a reason; using them improperly can potentially affect the structures of your eyes in a big way, Jennifer Fogt, O.D., an associate professor in the College of Optometry at The Ohio State University, tells SELF.

The good news is that avoiding the following mistakes can help you prevent a whole host of eye problems. Here are seven things eye doctors really wish you wouldn’t do with your contact lenses.

1. You let water come into contact with your lenses or their storage case.

Sometimes you run out of solution before you can get to the drugstore, and water does look like a fitting substitute, after all. But using water to store or rinse your contact lenses is a bad enough idea that the Centers for Disease Control and Prevention (CDC) specifically warns against it.

As the CDC points out, tap water (and even distilled water) can contain a microbe known as Acanthamoeba, which can stick to the surface of your contacts and infect your eyes. This is known as Acanthamoeba keratitis, and it can cause all kinds of problems like eye pain, eye redness, feeling like you have something in your eyes, blurred vision, sensitivity to light, and excessively watery eyes. Though Acanthamoeba keratitis may be treated with antibiotic eye drops, it can be hard to fully kick the infection since it can be resistant to meds, according to the Mayo Clinic.

Bottom line: Don’t rinse your contacts with water or use water to store them in their case. Instead, you should only use contact-care products specifically designed for those purposes, the CDC says.

2. You wear your contacts in the shower, the pool, and other bodies of water.

Unless you’re somehow swimming in a sea of contact solution, this is a bad idea. Exposing your contact lenses to water in a lake, pool, ocean, hot tub, or other body of water could lead to an Acanthamoeba infection, Dr. Fogt explains, just like exposing them to tap water might.

This doesn’t mean that if you’re at, say, the beach, you have to either wear your regular glasses or forego contact lenses and deal with impaired vision. Instead, ask your eye doctor about getting prescription sunglasses you can use in that kind of situation.

It can feel exasperating to pause before inserting or removing your contacts just so you can wash and dry your hands. But if you dive in with unwashed fingers, you’re giving all sorts of grubby germs easy access to your eyes, Dr. Fogt says.

To be clear, not all germs are actually pathogens that can cause issues with your eyes, but some might compromise your eye health. For example, keratitis, a painful inflammation of your corneas (the clear, dome-shaped layers of your eyes that help your vision focus), can happen due to microorganisms like bacteria, viruses, and fungi. You can introduce all of these into your eyes more easily with dirty hands, so wash them first.

4. You fall asleep without removing your contacts.

When you sleep in contact lenses, you’re reducing the amount of oxygen that gets to your eyes, Dr. Fogt says. That can lead to eye infections like keratitis. It can also bring about or exacerbate symptoms of dry eye. This condition happens when you don’t have sufficient tears to lubricate your eyes, and it can lead to redness, stinging, burning, scratchiness, sensitivity to light, and a feeling that something’s in your eyes, among other issues. According to the Mayo Clinic, contact lens wearers are more at risk of the condition in general, and sleeping in your lenses can just compound the problem.

Also, depending on the type you wear, leaving your contacts in overnight could mean you’re not cleaning them regularly, Corinne Casey, O.D., an optometrist with Katzen Eye Group, tells SELF. Allergens, various microorganisms, and protein deposits from your tear film all build up on the surfaces of your lenses during the day, Dr. Casey explains. If you have reusable contact lenses that your doctor says need to be cleaned every night, following those instructions is an important part of preventing problems.

Still, life happens. If you forget to take your contact lenses out before bed, you should remove them as soon as you wake up, Beeran Meghpara, M.D., an eye surgeon at Wills Eye Hospital, tells SELF. If they seem a little stuck in there (and they probably will), give your eyes a good rinse with sterile contact solution, close them, and rub your eyelids very gently before trying again, Dr. Meghpara says.

Once your contacts are out, it’s a good idea to wear your glasses for a few hours afterwards to let your eyes breathe, he says. And, of course, if you’re struggling to get the lenses out or you’re experiencing pain, sensitivity to light, discharge, or swelling, call your eye doctor right away so they can remove the lenses and check for infection.

5. You don’t replace your lenses as often as you should.

Every type of contact lens is different, but the AOA specifically says that you should always follow the recommended replacement schedule outlined by your doctor. (The Food and Drug Administration (FDA) regulates contact lenses and dictates how long you can safely wear each type of lens, so these guidelines are legit.)

Contacts aren’t cheap, so it’s no wonder why you’d want to get a little more bang for your buck by waiting to change them out. But using them for too long allows even more microorganisms, allergens, and protein deposits to build up and potentially cause inflammation, irritation, or infection. While cleaning your lenses as prescribed helps, that won’t necessarily get everything off, Dr. Casey says, so regularly swapping them out is key.

By the way, you should follow the replacement instructions no matter how often you actually wear your contacts during that time period, Dr. Fogt says. If you’re supposed to use a new set of contact lenses each month, do that even if you didn’t wear your contacts every day. Same goes for daily disposables—even if you didn’t actually wear them for the entire day, once you’ve used them, you should toss them.

6. You just top off the contact lens solution in your case instead of starting fresh.

Like the other tips here, this is all about keeping your contact lenses clean, Dr. Fogt says. While soaking your contacts in a solution-filled case can remove possible irritants from your lenses, that stuff can then stick around in the solution itself, Dr. Fogt says. That’s why the FDA recommends using fresh solution every time you’re cleaning and storing your lenses.

7. You don’t clean your contact case after every use, and you certainly aren’t cracking open a new one every every three months.

To truly get an A+ when it comes to caring for your contacts, you should be rinsing your case with sterile solution and letting it dry after every single use. Even then, it’s still not a sterile environment. To further reduce your risk of winding up with eye issues, the FDA says you should replace your contact case at least every three months, or however often your eye doctor tells you.

Even with the best contact lens hygiene in the world, you might still deal with eye issues that warrant a trip to the doctor. If you experience a ton of dryness, redness, pain, discharge, blurry vision, or anything else that makes your vision worse instead of better, Dr. Casey recommends you stop wearing your contacts and call your eye doctor right away. Getting into that exam room can help them figure out if you need a new type of contact lens, have an eye infection that needs treatment, or have another eye problem that needs attention.